Amongst other things, the fact that TDs with 55 range wouldn't stand a chance against tougher German armor that is backed up by a 60 range ATG, or the fact that it's one of the trade-offs for being an expensive late game vehicle that has bad armor and low health that doesn't have any AI damage at all, or the fact that the Panther is designed to counter mediums and heavies and not also tank destroyers.
The Allied Tank Destroyer profile isn't healthy, because their high penetration and regular/high DPM means they counter every type of vehicle, but their range is not the problem.
Sweet TD stats like 640 hitpoints, 160 armor, absolutely no anti-infantry, bad mobility and turret rotation in the case of the Firefly, and being a casemate in case of the SU-85? Don't just cherry pick. They have plenty of disadvantages compared to the Panther.
Im not sure a 5 range nerf will break Allies play. 55TD will still trade well over meds and heavy calls in. They will get the first and last shot of an engagement. You cannot really flank with a Tiger or KT. 55TD still have their pen, damages, rof, abilities. You can still complement them with Allies call ins. Nothing really changes in terms of counters imo.
But yes you are right, the only tougher german armor that changes with 55TD, is the panther supported by 60ATG. Which is the point, bingo! It brings panther back into the game. Which makes most sense for where all their costs stand. Now Panther plays are too passive, nothing about the dives or making use of the durablity.
55TD still have an advantage over Panthers, and why Allies shouldnt make more active support of their 55TD with 60ATG?
Yes you are right again on 55TD HP and armor, are of med class. But their guns are superb, which is enough for where their price stand. Low popcost also helps with support. As for SU85 and FF, i did suggest making SU85 tracking cheaper, and make FF tulips cheaper. These 2 tanks already have the sight advantage even as a 55TD. As repeated, Sov and Ukf can and do have tougher armor to supplement 55TD.
Im not sure how much changes we can go with 60TD's pen and rof. There seems to be no room to go except for superficial reduction. Reducing pen% from 90% to 87% or rof ttk from 10s to 10.2s (randon figures exampe), statistically, dont change anything except on paper.
55TD seems the most logical test, without affecting units from top to bottom. It seems to make Panther more exciting for its cost, again!
I know maybe my >1000 rank hold less weight. I hope more top players put their comments on a 55TD change. Perhaps there are more than meets the eye from different views.